Counterboring tool



PatentedlAug. l, 1922.

` CGUNTERBOR 0L.

A-PPLICATION FILED 9, |920.

rasant estesa,

JOEE' HUG@ SMITH, 0F DETROIT, MICHIGAN, ASSIGNQR TO THE ECLIPSE INTER-CHANGEABLE CGUNTERBOBE COMPANY, OF DETROIT, MICHIGAN, A CORPOB/A.

rien or lammeren.

OUNTEBBORING TOOL.

nasa-aas.

To lallwilzfom'1b/may comer/a:

Be it known that I, JOHN HUGO SMITH,

a citizen of the United States of America,

residing at Detroit, in the' county of Wayne and State of Michigan, haveinvented certain new and useful Improvements 1n Counterboring Tools, ofwhich'the following is a.

and its holder that will "not give rise to any etl 'snugly 'in thesocket B.

excessive stresses in the cutting member, such as might result inbreakage thereof, and which will not constitute any limltation to themachinin of the tool to form the cutting teeth thereo A preferredembodiment of the mvention is hereinafter fully described andillustrated in the accompanying drawings, wherein;-

`Figure l is a perspective view of a tool holding shank, machined inaccordance with the described invention for engagement with acounterboring tool;

Figure 2 is a perspective view of the counterbering tool which isadapted for en gagement with the shank shown .in Flg'ure l; :Figure isan nd view of said shank;

Figure 4 is an hxial sectional view, showing the tool in engagement withits holder. ln these views the reference .character A designates acounterboring tool having thev central socket B, and 'provided upon' itsunder face with the cutting member Flush with the top plate of thecutter A the same is integrally formed within the socket B with a pairof opposed' segmental ribs D,

the opposed faces-of said ribs-beingv plane and parallel, vand thecorners of .the rlbs heing square, as. is best shown in Figure 4.

.The cutter A is adat'ed to be mounted upon a rotative holder having theform of a cylindcalshank of a diameter to lengage To permit said shanktopass the ribs in entering said socket, the lower extremity of theshank is tened away at op osite `sides thereof, as

' indicated at F, the t ickness of material in- -Speeioation of LettersPatent.

Patenten nag. i, ieee;

Application led March 19, 1920., Serial. No. 367,158.

tervening between the faces F being substantially equal to the distancebetween the ribs D. The shoulders perpendicular to said faces, .andadjacent' ,to said shoulders the shank iscircumferentially notched, eachnotch cutting portions both of the planed face F and of the adjoiningcylindrical face of the shank.

The shoulders forming said notches are square, one of said shouldersbeing a conitinuation' of the shoulder F.

When the tool A has-heen slipped upon the shank E until the ribs l) ofsaid tool enshank to the tool and also to prevent Ashifting, of the toolaxially of the shank in either direction. To permit removal of the toolfrom the shank it is necessary only to first rotate the former relativeto the latter slightly in the direction of drive, so as to shift theribs l) out of the notches G and register said -ribs with the planedfaces F of the shank E; The bot-tom portion of the groove G remote fromthe intersected planed face F is' planed as indicated at G and thedrlving torque acts entirely between the planed faces G and the opposingVplaned faces of the ribs D. Thus, there can arise no axially actingcomponent of thedriving stress that might tend to result in breakageofthe tool A: Such stresses as arise from axial feeding of the 4tool aretransmitted --from the square shoulders of the notches G to the ribs Gand the relative proportioning of the parts is such that 1n case suchstresses become excessive the lmaterial of the shank E interveningbetween the end thereof andthe notch fG-will shear off before lsuchstresses are powerful enough to produce breakage of the tool.

In formin the described tool a bore is first produced centrally 'thereinsubstantially equal in diameter to the distance between the ribs D; TheboreiB is ythen produced by counterboring, the ounterbore terminatingglaned faces F lare terminated by.

nos

. tween said ribs to the diameter of the bore B.

the diameter of the walls intervening be- While the invention isdisclosed as applied to an inverted. counterboring tool, it is to beunderstood that it is equally applicable to a counterboring tool of thenon-inverted type as well as to other tools of various sorts. l

What li claim as my invention is:

l. The combination with a holder member, of a tool member detachablymounted. upon said holder member and adapted to be driven thereby, oneof said members being formed with a socket and the other having a shankforengagement with said socket, the socket forming member having a pairof oposed ribs Within its socket and said shank aving oppositelyarranged plane surfaces to pass between said ribs and being formedWith'oppositely arranged driving faces extending in rear of its planefaces, the latter being of greater depth than the depth of said ribs andsaiddriving faces being of substantially the same depth as said ribsleaving notched portions' engageable through a slight relative rotationof the holder member and tool member-after the initial insertion of theshank in the socket.

2. The combination with a holder member, of a tool member detachablymounted upon said holder member and adapted to be driventhereby, one ofsaid members being formed with asocket and the other having a shank forengagement with said socket, the socket forming member having a pair ofopposed ribs within its socket and said shank hav-ing oppositelyarranged lane surfaces to pass between said ribs and' eing formed withoppositely arranged driving faces extending in rear of its planefaces,the latter being of greater depth than the depth of said ribs andsaiddriving faces being of substantially the-same depth as' said ribsleaving notched portions engageable through a slight relative rotationof the holder member and tool member after the initial insertion of theshank in the socket whereby the notched portions are brought beneath the`opposed ribs and the driving surfaces have a relatively wide drivingengagement with the opposed ribs.

In testimony whereof aiix my signature.

Jona nUoo entre.

